Background : Nursing is the largest healthcare profession. It is critical to the quality of patient care and the success of any healthcare delivery system since nurses serve as the principal caregivers in hospitals and other institutional care settings. Their work requires a high degree of emotional labor. As Nurses are expected to display, emotions that convey caring, understanding, and compassion toward patients while they regulate their own feelings. This Study Aimed: To assess the relationship between job stress and head nurses job performance. Methods: An analytical correlation study, the population of the study included 30 head nurses' working in all units at four hospitals affiliated to the Ministry of Health namely: Port- Said general hospital (n=11units), Port- Fouad general hospital (n=10 units), El- Naser hospital (n=4 units), and El-Zohoor hospital (n=5 units).Data were collected using two structured questionnaires; the first one is the stress-rating questionnaire, the second tool is the job performance questionnaire.  Results: The results of the present study revealed that the majority of head nurses have high job stress level and poor job performance. Whereas there was no significant correlation between job performance and head nurses level of job stress.  Conclusion: Based on the results of the present study, it can be concluded that the head nurses working in all patient care units at four hospitals had experienced high level of job stress and poor job performance. To reduce the negative outcomes of stress, it was recommended that implement stress management-training program in hospitalss for all nurses in order to improve staff performance.